Generally, the widely-used peripheral input device of a computer system includes for example a mouse device, a keyboard device, a trackball device, or the like. Via the keyboard device, characters or symbols can be inputted into the computer system directly. As a consequence, most users and most manufacturers of input devices pay much attention to the development of keyboard devices.
The structures and the functions of a conventional keyboard device will be illustrated as follows. FIG. 1 is a schematic side view illustrating a conventional keyboard device. For succinctness, only one key 11 and the related components are shown in FIG. 1. It is noted that the number of the keys 11 is not restricted. The conventional keyboard device 1 comprises plural keys 11, a base plate 15 and a membrane circuit board 14. The membrane circuit board 14 is arranged between the key 11 and the base plate 14. Each of the plural keys 11 comprises a keycap 111, a connecting element 12 and an elastic element 13. The connecting element 12 is connected between the keycap 111 and the base plate 15. Consequently, the keycap 111 is movable upwardly or downwardly relative to the base plate 15. The elastic element 13 is arranged between the keycap 111 and the base plate 15. Moreover, the elastic element 13 comprises a contacting part 131.
The connecting element 12 is a scissors-type connecting element. Moreover, the connecting element 12 comprises a first frame 121 and a second frame 122. The second frame 122 is pivotally coupled to the first frame 121. The two ends of the first frame 121 are connected with the keycap 111 and the base plate 15, respectively. The two ends of the second frame 121 are also connected with the keycap 111 and the base plate 15, respectively. Due to the above structure, the first frame 121 and the second frame 122 can be swung relative to each other. Consequently, the first frame 121 and the second frame 122 are switched from a stacked state to an open-scissors state or switched from the open-scissors state to the stacked state.
The membrane circuit board 14 comprises key switches (not shown). While the keycap 111 of any key 11 is depressed and moved downwardly relative to the base plate 15, the first frame 121 and the second frame 122 of the connecting element 12 are switched from the open-scissors state to the stacked state. Moreover, as the keycap 111 is moved downwardly to compress the elastic element 13, the corresponding key switch is pushed and triggered by the contacting part 131 of the elastic element 13. Consequently, the keyboard device 1 generates a corresponding key signal. When the keycap 111 of the key 11 is no longer depressed, the keycap 111 is moved upwardly relative to the base plate 15 in response to an elastic force of the elastic element 13. Meanwhile, the first frame 121 and the second frame 122 are switched from the stacked state to the open-scissors state again, and the keycap 111 is returned to its original position.
With increasing development of science and technology, the functionality of the keyboard device 1 is gradually enhanced and thus the demands of the user on the keyboard device 1 are gradually increased. For example, the keycap 111 of the general keyboard device 1 is made of a plastic material. However, some users prefer to change the style or the material of the keycap 111. For example, the users prefer that some of the keycaps 111 are made of a wood material, a leather material or any other appropriate material. As known, it is difficult for the general users to disassemble the keycaps 111 of the conventional keyboard device 1. During the process of disassembling the keycaps 111, the connecting element 12 or other components are readily suffered from damage.
In other words, the conventional keyboard device needs to be further improved. Therefore, there is a need of providing a keyboard device with easily-changeable keycaps.